Functional movement analysis in patients with chronic nonspecific low back pain: a reliability and validity study

Background Individuals afflicted with nonspecific chronic low back pain (CLBP) exhibit altered fundamental movement patterns. However, there is a lack of validated analysis tools. The present study aimed to elucidate the measurement properties of a functional movement analysis (FMA) in patients with CLBP. Methods In this validation (cross-sectional) study, patients with CLPB completed the FMA. The FMA consists of 11 standardised motor tasks mimicking activities of daily living. Four investigators (two experts and two novices) evaluated each item using an ordinal scale (0-5 points, one live and three video ratings). Interrater reliability was computed for the total score (maximum 55 points) using intra class correlation and for the individual items using Cohen's weighted Kappa and free-marginal Kappa. Validity was estimated by calculating Spearman's Rho correlations to compare the results of the movement analysis and the participants' self-reported disability, and fear of movement. Results Twenty-one participants (12 females, 9 males; 42.7 +/- 14.3 years) were included. The reliability analysis for the sum score yielded ICC values between .92 and.94 (p < .05). The classification of individual scores are categorised 'slight' to 'almost perfect' agreement (.10-.91). No significant associations between disability or fear of movement with the overall score were found (p > .05). The study population showed comparably low pain levels, low scores of kinesiophobia and disability. Conclusion The functional movement analysis displays excellent reliability for both, live and video rating. Due to the low levels of disability and pain in the present sample, further research is necessary to conclusively judge validity.